The packaged version in Qubes OS repos do not work for R4.2 rc2. I had to compile i3 using qubes-builder according to this forum post: Has anyone installed i3wm 4.22.
To successfully compile for R4.2 rc2 and above, you would need to use a Fedora qube as your compile environment with SELinux disabled.
Disable SELinux with sudo setenforce 0 and sudo setenforce Permissive.
Modify builder.conf in the post to include the option DIST_DOM0 ?= fc37 before the line that contains include and change the release version to 4.2. To install the compiled packages in dom0 you need to install xautolock using qubes-dom0-update.
Credits to @DVM for the tutorial and fixes in the original post.